Brake beam

ABSTRACT

A brake beam assembly comprised of a compression member with a first end and a second end, a tension member with a third end and a fourth end, a strut connected to the tension member and the compression member, a first brake head, and a second brake head. The ends of the compression and tension members each contain at least two holes in which is disposed a fastener. At least one of the ends of the compression member and the end of said tension member is contiguous with each of the first brake head and the second brake head, and with the exception of the compression member, the tension member, and the fasteners, no other structural member is contiguous with the brake heads.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a continuation-in-part of applicant's patentapplication U.S. Ser. No. 08/715,619, filed on Sep. 13, 1996, now U.S.Pat. No. 5,810,124 issued Sep. 22, 1998.

FIELD OF THE INVENTION

A brake beam for use on railroad car trucks.

BACKGROUND OF THE INVENTION

Brake beams are well known to those in the art and have been used withrailroad car trucks for at least ninety years.

One such brake beam is disclosed in U.S. Pat. No. 2,517,747 of L. L.Whitney, which is assigned to American Steel Foundries of Chicago, Ill.;the entire description of this patent is hereby incorporated byreference into this specification.

This Whitney patent describes a hanger type brake beam comprising acompression member having top and bottom webs and a front web, a fillerblock externally of the space between said top and bottom webs, bearingagainst the forward surface of said front web and having an arcuateopening extending from the inboard to the outboard end of said block, atension member of uniform cross-section from end to end thereof havingan end portion bent approximately parallel to said front web, saidportion being snugly fitted in said opening, a brake head having acavity receiving said block, said portion and said webs, said break headhaving top and bottom rear walls connected to said top and bottom webs,said block and said portion, said connection extending lengthwise ofsaid front web and being spaced from but extending adjacent to theinboard and outboard ends of the block.

The structure of the Whitney patent, in addition to being relativelyheavy and cumbersome, provides relatively poor static strength andfatigue strength properties in use.

Another prior art brake beam of hangerless or unit type design isdisclosed in U.S. Pat. No. 2,170,121 of C. R. Busch; the entiredisclosure of this patent is also hereby incorporated by reference intothis specification. This patent discloses a brake beam, including achannel section forming a compression member having its greatest depthat its middle portion, and which, toward its ends, gradually tapersdown, and a tension member having its ends firmly attached to the endsof the compression member, the attached ends of the members allextending beyond the points of location for brake heads to guide thebeam on car truck frames.

The brake bream device of this Busch patent also is relatively heavyand, per unit weight, provides relatively poor static strength andfatigue resistance properties.

By way of further illustration, other United States patents havedisclosed various brake beam designs; none of them, however, haveprovided a unit brake beam with substantially improved static strengthand fatigue strength properties per unit weight. Thus, illustrative ofthese prior art failed designs are the structures disclosed in U.S. Pat.No. 2,427,548 (integral brake beam with cruciform cross section), U.S.Pat. No. 2,499,905 (brake beam with integral truss and brake heads),U.S. Pat. No. 2,170,122 (brake beam with built-up compression andtension members), U.S. Pat. No. 2,193,580 (brake bream with broadsurface for saddle of brake beam strut), and the like. The disclosuresof these patents are also incorporated by reference into thisspecification.

It is an object of this invention to provide a brake beam structurewhich is relatively light weight but, also, has relatively high staticstrength and fatigue resistance properties.

It is another object of this invention to provide a brake breamstructure which is substantially more durable and less likely toself-destruct during use than comparable multi-piece prior art brakebeam devices.

It is another object of this invention to provide a brake beam structurewhich is greatly simplified and substantially easier to manufacture thanprior art assemblies.

It is yet another object of this invention to provide a novel processfor producing the brake bream structure of the invention.

SUMMARY OF THE INVENTION

In accordance with this invention, there is provided a brake beamassembly comprised of a compression member with a first end and a secondend, a tension member with a third end and a fourth end, a strutconnected to the tension member and the compression member, a firstbrake head, and a second brake head. The ends of the compression andtension members each contain at least two holes in which is disposed afastener. At least one of the ends of the compression member and the endof said tension member is contiguous with each of the first brake headand the second brake head, and with the exception of the compressionmember, the tension member, and the fasteners, no other structuralmember is contiguous with the brake heads.

Although the preferred embodiment of this invention is illustrated withregard to a hangerless or unit brake beam, the invention is equallyapplicable to a hanger type brake beam.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood by reference to thefollowing detailed description thereof, when read in conjunction withthe attached drawings, wherein like reference numerals refer to likeelements, and wherein:

FIG. 1 is a broken plan view of a car truck 10 within which is disposeda brake beam assembly.

FIG. 2 is a first perspective view of one preferred embodiment of thebreak beam of this invention.

FIG. 3 is a second perspective view of the preferred embodiment of FIG.2.

FIG. 4 is a plan view of the brake beam unit of FIG. 2.

FIGS. 5, 6, and 7 are plan, side, and front views, respectively oftension member 52.

FIGS. 8, 9, and 10 are plan, front, and side views, respectively, ofcompression member 54.

FIGS. 11 and 12 are side and top views, respectively, of brake head 58.

FIGS. 13 and 14 are perspective views of brake head 58.

FIG. 15 is a sectional view of a brake head 58 and its associated brakeshoe assembly.

FIGS. 16A, 16B, and 16C are sectional views of a brake head shoe and keyassembly.

FIGS. 17A and 17B are side and end views, respectively, of a side framewear plate.

FIG. 18 is an end view of another wear plate.

FIG. 19 is a plan view of a beam assembly disposed within a truck sideframe.

FIG. 20 is a perspective view of a brake beam strut.

FIGS. 21A and 21B are a side view and a sectional view of the brake beamstrut of FIG. 20.

FIG. 22 is a plan view of the brake beam strut of FIG. 20 disposedwithin the tension member.

FIGS. 23A and 23B are sectional views of the brake beam strut of FIG. 20attached to the compression member.

FIGS. 24 is a partial sectional view illustrating the brake beam strutof FIG. 20 attached to the compression member.

FIGS. 25A and 25B are side views of a strut bushing assembled into thebrake beam strut.

FIGS. 26A, 26B, 26C and 26D, are plan views illustrating the brake beamassembly at various points in its assembly process.

FIG. 27 an exploded view of the preferred brake beam assembly hardware,illustrating how it is configured.

FIGS. 28A, 28B, and 28C are exploded views of preferred brake beamassembly fasteners.

FIGS. 29A, 29B, and 30 are views of other brake beam assembly fasteners.

FIGS. 31A, 31B 31C, 31D, 31E are perpspective views of another preferredbrake beam assembly of the invention in which there is no recess.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a broken plan view of a car truck 10. Provided within cartruck 10 is brake beam assembly 12, supported on guides 14 and 16located adjacent to the wheels 18 and 20. A lever (not shown) insertedwithin slot 22 applies force in the direction of arrows 24 and 26. Whenforce is applied in the direction of arrow 24, the beam 12 moves in thedirection arrow 24 so that brake shoes 28 and 30 contact wheels 18 and20, respectively.

As is known to those skilled in the art, because of the substantialspeeds at which railroad cars travel and the heavy loads they carry,large braking forces are required to be transferred to the wheelsthrough the brake beam assemblies during their operation. These forces,and random vibrations borne through the truck structure to the brakebeams, create stresses in areas such as areas 32, 34, 36, 38, 40, 42,44, and 46.

The railroad industry has expressed concern about the safety record ofthe United States railroad system. Applicants' brake beam device hasbeen developed in response to such concern.

FIG. 2 is a perspective view, taken above and from the back, of thebrake beam unit 50 of this invention. Referring to FIG. 2, it will beseen that brake beam unit 50 is comprised of a rectiliner tension member52, a rectilinear compression member 54, strut 56 joining members 52 and54, brake heads 58 and 60 with recesses (not shown) within which members52 and 54 partially nest, fasteners 62 and 64 which connect brake heads58 and 60 to members 52 and 54, and a fastener 66 (not clearly shown inFIG. 2) connecting strut 56 to compression member 54.

FIG. 3 is another perspective view of brake beam unit 50, taken frombelow unit 50 and to its front. Fastener 66 is more clearly indicated inFIG. 3.

FIG. 4 is a plan view of the brake beam unit 50. In this embodiment, theunit has only two fasteners 63 per end, the unit 50 has an overalllength 68 of from about 69 to 70 inches, an overall distance 70 to theoutside of the brake heads 58 and 60 of from about 63 to 64 inches, adistance 72 between the centerlines of the brake heads 58 and 60 of fromabout 60 to 61 inches, a distance 74 from the centerline of the beamunit 50 to the centerline of either brake head 58 or 60 of from about29.5 to about 30.5 inches, a clear distance 76 from the end of beam 50to either brake head 58 or 60 of from about 2.5 to about 3.5 inches, adistance 78 from the centerline face of brake head 58 (or 60) to thecenterline of the strut pinhole 80 of from about 1 to about 1.5 inches,a length 82 of the strut lever slot 22 of from about 7.5 to about 8.5inches, a distance 84 from point 86 (at the back of compression member54) to the centerline of pinhole 80 of from about 7.5 to about 8.5inches, and a depth 88 from point 86 to the nose 90 of tension member 52of from about 17 to about 18 inches.

In one embodiment, the dimensions of brake beam unit 50 are insubstantial accordance with the Association of American Railroads'"Manual of Standards and Recommended Practices", Section D, Trucks andTruck Details, Standard S-345-79 (Adopted 1875, Revised 1979),"Application Tolerances for Brake Beams, Hangerless Types" (See FIG. 12,page D-213).

Tension Member 52

FIG. 5 is a plan view of tension member 52. Because of its uniquegeometry and construction, it is especially suited for use inapplicants' brake beam 50.

FIG. 6 is a side view of tension member 52. It will be seen that, in thepreferred embodiments depicted in FIGS. 5 and 6, tension member 52 has asubstantially "flat" cross-sectional shape. Thus, referring to FIG. 6,it will be seen that upper surface 92 and lower surface 94 aresubstantially parallel to each other, thereby producing the desired flatstructure 52 which consequently can be within the recess (not shown) inbrake head 58 and/or 60. Alternatively, one may use members with othercross-sectional shapes. As will be apparent to those skilled in the art,as long as there is at least one leg with two substantially parallelsides, other structural members may be present in tension member 52.

In one embodiment, not shown, tension member 52 forms an angle of about90 degrees throughout its length.

Referring again to FIG. 6, it is preferred that tension member 52 have across-sectional area of from about 0.5 to about 5.0 square inches and,more preferably, from about 1.0 to about 3.0 square inches. In an evenmore preferred embodiment, the cross-sectional area of tension member 52is from about 1.2 to about 2.0 square inches.

The cross-sectional area of tension member 52 is the product of itswidth 96 and its thickness 98 (see FIG. 7).

Referring to FIG. 5, width 96 is preferably substantially constant overits entire length; and width 96 preferably is from about 1 to about 4inches. In a more preferred embodiment, width 96 is from about 2 toabout 3 inches.

In addition to having a constant width 96, tension member 52 preferablyis comprised of parallel walls 107 and 109, and 111 and 113 which, whenthey extend past arcuate section 112 on either side, are substantiallystraight, without any bends.

Referring again to FIG. 7, walls 107 and 111 are cut to form notchedsections 114 and 116. Notched sections 114 and 116 preferably will besubstantially contiguous with surfaces 118 and 120 of compression member54 (see FIG. 4).

Referring to FIG. 7, thickness 98 is preferably from about 0.25 to about4 inches. In a more preferred embodiment, thickness 98 is from about0.35 to about 1.0 inches.

It is preferred that tension member 52 be comprised of or consistessentially of a material such that, with the preferred cross-sectionalarea, member 52 have a yield strength of from about 20,000 to 100,000pounds per square inch and, more preferably, from about 30,000 to about60,000 pounds per square inch. In one embodiment, tension member 52consists essentially of carbon steel with a carbon content of from about0.05 to about 0.8 percent.

It is also preferred that tension member 52, with the specifiedcross-sectional area, have an elongation at break of at least abouteight percent and, more preferably, at least about 12 percent.

Referring again to FIG. 5, and in the preferred embodiment depictedtherein, it will be seen that tension member 52 preferably has anoverall length 100 of from about 50 to about 70 inches and, morepreferably, from about 60 to about 65 inches. Inasmuch as tension member52 is preferably symmetrical around its midpoint 102, distance 102 ispreferably at one-half of distance 100.

Referring again to FIG. 5, it will be seen that tension member 52preferably has a depth 104 (as measured from the deepest portion ofinternal bend radius 106) of from about 5 to about 17 inches and, morepreferably, from about 10 to about 15 inches.

Referring again to FIG. 5, it will be seen that tension member 52 iscomprised of legs 108 and 110 which are integrally connected to eachother through arcuate section 112. The angle 114 formed between legs 108and 110 is preferably greater than about 105 degrees and, morepreferably, is from about 110 to about 150 degrees. In one embodiment,angle 114 is from about 120 to about 140 degrees.

Compression Member 54

FIG. 8 is a plan view of compression member 54. Because of its uniquegeometry and construction, it is especially suited for use inapplicants' brake beam 50.

Referring to FIGS. 8, 9, and 10 it will be seen that compression member54 is preferably comprised of legs 126 and 128 (see FIG. 10) whichextend through substantially its entire length 130 (see FIG. 8).

Referring to FIG. 10, and in the preferred embodiment depicted therein,legs 126 and 128 for a substantially ninety degree angle between them.As will be apparent to those skilled in the art, this configurationaffords substantial column strength to member 54. Means for measuringand calculating the column strength of structural members are well knownto those skilled in the art. Reference may be had, e.g., to U.S. Pat.Nos. 5,419,373, 5,409,470, 5,403,292, 5,322,213, 5,279,442, 5,217,128,and the like. The disclosure of each of these United States patents ishereby incorporated by reference into this specification.

As will be apparent to those skilled in the art, differentcross-sectional shapes will afford different amounts of column strengthper unit weight. A square tubular shape, or a rectangular tubular shape,gives good results. A cruciform shape also gives relatively goodresults.

In one preferred embodiment, illustrated in FIG. 10, the compressionmember is in the form of a right angle. In the preferred embodimentdepicted in FIG. 10, leg 126 has thickness 125 of from about 0.1 toabout 0.5 inches and, more preferably, from about 0.2 to about 0.4inches. Leg 126 preferably has a length 127 of from about 0 to 5 inchesand, preferably, from about 2 to about 4 inches.

Similarly, leg 128 has a thickness 131 of from about 0.1 to about 1.0inches and, more preferably, from about 0.2 to about 0.4 inches. Leg 128has a length 133 of from about 1 to about 5 inches and, more preferably,from about 2 to about 4 inches.

It is preferred that compression member 54 be comprised of or consistessentially of a material such that it have a yield strength of fromabout 20,000 to 100,000 pounds per square inch and, more preferably,from about 30,000 to about 60,000 pounds per square inch. In oneembodiment, compression member 54 consists essentially of carbon steelwith a carbon content of from about 0.05 to about 0.8 percent.

It is also preferred that compression member 54 have an elongation atbreak of at least about eight percent and, more preferably, at leastabout 12 percent.

Referring to FIG. 8, and in the preferred embodiment depicted therein,it will be seen that compression member 54 preferably has an overalllength 130 of from about 50 to about 70 inches and, more preferably,from about 60 to about 65 inches. Inasmuch as compression member 54 ispreferably symmetrical around its midpoint 135, distance 133 ispreferably at one-half of distance 130.

Referring again to FIG. 8, it will be seen that compression member 54 iscomprised of end sections 132 and 134 which are partially disposedwithin a recess (not shown) in each of brake heads 58 and 60 (see FIG.2). The end sections 132 and 134 preferably contain flat, substantiallyparallel surfaces 136,138 and 140,142 which are adapted to fit withinsuch recess (not shown). Each of end sections 132 and 134 will have alength 144 (which may be identical or different) of from about 2 toabout 12 inches and, more preferably, from about 6 to about 10 inches.

Referring to FIG. 9, and in the preferred embodiment depicted therein,it will be seen that end compression member 54 is comprised of a firstsection 146 and a second section 128. The base leg 152 of section 146 isnot coplanar with the base 154 leg of section 148; an offset 150 of fromabout 0 to about 2.0 inches is preferably used. In one preferredembodiment, offset 150 is from about 0.5 to about 1.5 inches. As isknown to those skilled in the art, the term "sweep" is often used todescribe such an offset.

FIG. 8 is a view of compression member 54 taken from its top. As isshown by this plan view, compression member 54 is preferably offset intwo different directions which are orthogonal to each other.

Referring to FIG. 8, it will be seen that compression member 54 iscomprised of upright leg 156 and upright leg 158, which are not coplanarwith each other. Leg 158 has an offset (camber) 160 from leg 156 of fromabout 0 to about 2.0 inches. In one preferred embodiment, theoffset/camber 160 is from about 0.5 to about 1.5 inches. Referring againto FIG. 8, it will be seen that each of sections 146 and 148 arecomprised of flat surfaces 164 and 162 which are adapted to besubstantially contiguous with notched sections 114 and 116 (see FIG. 5).Furthermore, each of sections 146 and 148 are comprised of end walls 168and 166 which are adapted to be substantially contiguous withcorresponding surfaces (not shown) of brake heads 58 and 60.

It will be seen that, in the preferred embodiment illustrated in FIG. 8,inside surface 162 is substantially coplanar with inside surface 161 ofleg 158. Similarly, inside surface 164 is substantially coplanar withinside surface 163 of leg 156. As will be apparent to those skilled inthe art, because of the pitch on compression member 54, the 1:20 faceangle required for brake heads 58 and 60 may be obtained withoutadditional structural modifications.

Referring again to FIG. 8, at about its midpoint 135, base legs 152 and154 are joined (see FIG. 9), and at this juncture this is asubstantially coplanar section 170 extends from about point 172 to about174 and is preferably from about 2 to 4 inches in length.

Brake Head 58

FIGS. 11 and 12 are side and top views, respectively, of brake head 58which, as will be apparent to those skilled in the art, is preferablysubstantially identical to brake head 60.

The brake head 58 illustrated in FIGS. 11 and 12 are configured insubstantial accordance with the aforementioned Association of AmericanRailroad's "TRUCKS AND TRUCK DETAILS" publication. In particular, theseembodiments are in substantial accordance with pages Standard S-371-81,"LIMITING CONTOUR OF BRAKE HEADS FOR HANGERLESS TYPE BRAKE BEAMS", whichappears on page D-250 of such publication. Referring to FIGS. 11 and 12,it will be seen that brake head 58 (and brake head 60) is comprised of arecess defined by flat, parallel, inner surfaces 176 and 178.

Referring to FIG. 12, it will be seen that tension member 52 iscomprised of linear surface 113 which, in part, abuts a portion ofarcuate surface 180. Because of the curved nature of surface 180,varying the length of distance 72 of assembly 50 while keeping distance88 constant (see FIG. 4) will allow surface 180 to compensate for suchvariation and to maintain substantially broad contact between it linearsurface 113.

Referring again to FIGS. 11 and 12, it will be seen that surface 180 isalso comprised of arc 182 which, when the assembly 50 under loadedconditions deflects, compensates for such deflection.

Referring to FIGS. 11 and 12 (and also to FIG. 13), it will be seen thatbrake head 58 is comprised of inner surface 184 which is adapted toreceive surface 168 of compression member 54.

Referring again to FIG. 11, it will be seen that brake head 60 iscomprised of a split flange 186; this split flange is illustrated in bydotted lines in FIG. 14.

It will be seen from FIG. 12, e.g., that fasteners 62 which securetension member 52 to brake head 60 are not colinear. Three fasteners 62are used in this assembly, although four or more fasteners also may beused.

Without wishing to be bound to any particular theory, applicants believethat, under load, area 190 of compression member 54 makes contact withthe underside of area 192 of tension member 52. Because of the nestingarrangement of members 52 and 54, this movement is limited.

FIG. 13 is a perspective view of brake head 60, illustrating arc surface182 tapering away from the tension member (not shown), and also showingsurface 184, which contacts the end of the compression member (notshown).

FIG. 14 is perspective view of brake head 60, showing, in dotted lineoutline, split flange 186 and an extension 188. It will be seen that akey guide 194 provides a raised passageway for a brake key (not shown inFIG. 14). Key latch 196 is adapted to retain the key (not shown) withinthe key guide.

FIG. 15 is an exploded sectional view illustrating the key assembly.Referring to FIG. 15, it will be seen that a key 198 is disposed withinkeyway tunnel 200. Within keyway tunnel 200 is a raised surface, keyguide 194, which causes the end 202 of key 198 to be shifted upwardly sothat it can enter the slot 204 in brake shoe lug 206. As will beapparent to those skilled in the art, if key guide 194 were notprovided, key 198 would be allowed to pass behind the tip 208 of brakeshoe lug 206 and, thus, would not engage brake shoe 28 via slot 204.

FIG. 16C illustrates a key 198 fully installed in a key assembly; FIGS.16B and 16C illustrate the key 198 partially removed from the keyassembly.

FIG. 16A illustrates one embodiment of a brake key assembly in which key198 has a region 210 comprised of multiple pleats which are adapted toengage the bottom inside tip 212 of the keyway tunnel 200. These pleatsare provided in substantial accordance with the Association of AmericanRailroads "Brake Shoe Keys Standard" S-376 (see page D256).

FIGS. 16B and 16C illustrate a modified keyway tunnel 200 comprised of araised section 196 (key latch 196) which is adapted to interlock withpleated section 210. As those skilled in the art will be aware, theprovision of key latch 196 provides a safety factor for retaining thekey 198 within the keyway; and it also deters the complete removal ofsuch key 198.

As will be apparent from FIG. 16C, when key 198 is in its fullyinstalled position, it is not contiguous with key latch 196, and itsservice life is thus not appreciably affected by such key latch 196.Only when key 198 is partially removed (see FIGS. 16A and 16B) does itcontact the key latch 196, which inhibits its complete removal.

FIGS. 17A and 17B, and 17C are plan and end views, respectively, oftruck side frame wear plate 214, which preferably consists essentiallyof either steel or plastic. In the preferred embodiment depicted, it ispreferred that each of ears 216 have a thickness 218 which is less thanabout 0.19 inches and, more preferably, less than about 0.16 inches. Inone embodiment, side frame wear plate 214 consists essentially ofpolyurethane.

FIG. 18 shows another embodiment of a truck side frame wear plate 215 inwhich lips 216 are omitted. In this embodiment, it will be seen thatwear plate 215 is comprised of openings 220 (shown in dotted lineoutline) which are adapted to facilitate the removal of the wear plate15.

FIG. 19 is plan view of the brake beam 50 connected to side frame 10.Referring to FIG. 19, it will be seen that there is a gap 224 betweenthe tip 222 of the brake beam end extension and the inside bottomsurface 226. There is also a gap 228 between the outside surface 230 ofthe brake head 60 and the outer surface 232 of the wear plate liner 214.It will be seen, because of the preferred configuration of applicants'assembly, gap 228 is greater than gap 224. It is preferred that gap 228be greater than gap 224 by at least about 0.03 inches and, morepreferably, by at least about 0.06 inches. As will be apparent to thoseskilled in the art, this end is achieved by either reducing thethickness 218 and/or removing lip 216; and this result reduces thepossibility of brake beam binding.

FIG. 20 is a perspective view of strut 56 which is preferably comprisedof slots 234, 236, 238, and 240, which are adapted to engage the tensionmember 52 (see FIG. 2). It will also be seen that strut 56 is comprisedof tail support 242 comprising legs 244 and 246 which are adapted toengage compression member 54 (see FIG. 2). Strut pin hole 80 is adaptedto receive a bushing (not shown).

FIGS. 21A and 21B are side and sectional views, respectively of strut56. It will be seen that, in the preferred embodiment depicted, thestrut 56 is comprised of a tube-shaped steel assembly 248.

FIG. 22 is a plan view of strut 56 engaging tension member 52. In theembodiment depicted, the perimeter 250 of strut 56 intersects tensionmember 52 at tangent points 252 and 254, thus providing a substantialamount of stability and self-centering. It is preferred that thediameter of strut 56 be at least from about 2 to about 5 inches.

Referring again to FIG. 22, contact surfaces 256, 258, 260, and 262 helpprovide such stability. Contact surfaces 256 and 258 each have a pitchwhich is smaller than the pitch of contact surfaces 260 and 262, therebyinsuring contact at points 252 and 254. As the assembly is loaded,contact will be made at the desired contact surfaces 256, 258, 260, and262.

As will be apparent to those skilled in the art, because contact occursat at least two locations (256 and 258) rather than at only a singlelocation reduces the potential fatigue failure at any one point.

Referring again to FIG. 22, it will be seen that slots 234 and 238provide substantial interlock between strut 56 and tension member 52.Reference also may be had to FIG. 2, which shows such interlock.

FIGS. 23A and 23B are sectional end views of strut 56, illustrating therelative positions of slot pairs 234/238 and 236/240 and legs 244 and246.

FIG. 24 is a partial sectional view illustrating the connection betweentension member 54 and strut 56 with fastener 66. As will be apparent tothose skilled in the art, fastener 66 is loaded in shear, therebyproviding a simplified assembly.

FIGS. 25A and 25B are partial side views of strut 56. It will be seenthat strut 56 is adapted to receive either bushing 264 and bushing 266.The outside diameter of both of these bushings is identical, but theinside diameters are varied. Thus, with the use of one strut 56 withonly one strut pinhole 80, bushings with different inside diameters canbe used. As will be apparent to those in the art, different bushings areused to control the application of different capacity beams in brakesystems.

FIG. 26A is a tension member 52 prior to the time any other componentshave been attached to it. In the assembly step illustrated in FIG. 26B,tension member 52 is inserted into brake heads 58 and 60 which arelocated at controlled positions 268 and 270.

In the assembly step illustrated in FIG. 26C, a subassembly 274 isconstructed by joining strut 56 to compression member 54 by means offastener 66.

In the assembly step illustrated in FIG. 26D, subassembllies 272 and 274are joined by inserting subassembly 274 into subassembly 272, therebyproducing new subassembly 276. Thereafter, at points 278 and 280, forcesare sequentially applied by means of clamps (or other suitable means) tocause contact between surface 168 at the end of compression member 54,and surface 184 on brake head 60 (see FIG. 12). As will be apparent tothose skilled in the art, because of the symmetry of the beam, a similareffect occurs at the interface between brake head 58, and thecompression member 54. Subsequently, and similarly, forces are thenapplied at points 282 and 284 to compress the ends of bar 52 betweencompression member 54 and brake heads 58 and 60.

The compressed structure thus produced is identified as subassembly 276.Thereafter, holes 286 and 288 are drilled in the assembly to receivefasteners (not shown).

FIG. 27 is a partial exploded view of subassembly 276. Fasteners 66 arepreferably inserted through holes 286 and 288 and secured with fastenerscollars 290.

In the preferred process illustrated in FIG. 27, lower and uppermandrels 292 and 294 are used to force collars 290 onto the fasteners 66and to swage them into final fastening position. It will be noted thatlower mandrel 292 preferably contains preloading springs 296 and 298adapted to clamp the beam assembly 276 prior to swaging collars 290.

FIGS. 28A, 28B, and 28C illustrates a two piece rivet 300 which can beused which is comprised of a pin 302 and a collar 304. FIGS. 29A and 29Billustrate an bolt 308/nut 310 fastener. FIG. 30 illustrates a solidintegral rivet 312 which also may be used. A welded joint (not shown)also may be used.

FIGS. 31A, 31B, 31C, 31D, and 31E are perspective views of anotherpreferred embodiment of the brake beam of the invention in which thereare no recesses.

Referring to FIG. 31A, it will be seen that brake beam assembly 330 issimilar to the brake beam assembly 50 depicted in FIG. 3 but does notcontain the recess and the lower flange depicted in such Figure.

FIG. 31B is a side elevational view of brake beam assembly 330illustrating the absence of such lower flange and recess.

FIG. 31C is a side elevational view of a brake beam assembly 340 inwhich the arrangement of the tension member 52 and the compressionmember 54 is reversed from their position in FIG. 31B.

FIG. 31D is also a side elevational view of a brake beam assembly 350 inwhich the arrangement of the tension member 52 and the compressionmember 54 differs from the arrangements utilized in FIGS. 31A, 31B, and31C.

FIG. 31E is also a side elevational view of a brake beam assembly 360 inwhich the arrangement of the tension member 52 and the compressionmember 54, and the means for fastening these members to the brake head,differs from that depicted in FIGS. 31A, 31B, 31C, and 31D.

It is to be understood that the aforementioned description isillustrative only and that changes can be made in the apparatus, in theingredients and their proportions, and in the sequence of combinationsand process steps, as well as in other aspects of the inventiondiscussed herein, without departing from the scope of the invention asdefined in the following claims.

I claim:
 1. A brake beam assembly comprised of a compression member witha first end and a second end, a tension member with a third end and afourth end, a strut connected to said tension member and saidcompression member, a first brake head, and a second brake head,wherein:(a) said first end and said second end of said compressionmember and said third end and said fourth end of said tension member areeach comprised of a first hole, a second hole, and a third holeextending completely through said end; (b) disposed within each of saidfirst hole is a first fastener, disposed within each of said second holeis a second fastener, and disposed within each of said third hole is athird fastener; and (c) at least one of said first end of saidcompression member and said third end of said tension member iscontiguous with said first brake head, and at least one of said secondend of said compression member and said fourth end of said tensionmember is contiguous with said second brake head, and with the exceptionof said compression member, said tension member, said first fastener,said second fastener, and said third fastener, and no other structuralmember is contiguous with said first brake head or said second brakehead; and (d) wherein said tension member is comprised of a firstparallel wall and a second parallel wall which extend from a middlesection to a first end section and a second end section, provided that,when said first parallel wall and said second parallel wall extend pastsaid section towards said first end section and said second end section,they are substantially straight without any bends.
 2. The brake beamassembly as recited in claim 1, wherein said third hole is not colinearwith said second hole and said first hole.
 3. The brake beam assembly asrecited in claim 1, wherein said tension member has an upper surface anda lower surface which are substantially parallel to each other.
 4. Thebrake beam assembly as recited in claim 1, wherein said tension memberhas a cross-sectional area of from about 0.5 to about 5.0 square inches.5. The brake bream assembly as recited in claim 1, wherein said tensionmember has a cross-sectional area of from about 1.2 to about 2.0 squareinches.
 6. The brake beam assembly as recited in claim 1, wherein saidtension member has a first notched section and a second notched section.7. The brake beam assembly as recited in claim 6 wherein each of saidfirst notched member and said second notched member is substantiallycontiguous with said compression member.
 8. brake beam assemblycomprised of a compression member with a first end and a second end, atension member with a third end and a fourth end, a strut connected tosaid tension member and said compression member, a first brake head, anda second brake head, wherein:(a) said first end and said second end ofsaid compression member and said third end and said fourth end of saidtension member are each comprised of a first hole and a second holeextending completely through said end; (b) disposed within each of saidfirst hole is a first fastener, and disposed within each of said secondhole is a second fastener; (c) at least one of said first end of saidcompression member and said third end of said tension member iscontiguous with said first brake head, and at least one of said secondend of said compression member and said fourth end of said tensionmember is contiguous with said second brake head, and with the exceptionof said compression member, said tension member, said first fastener andsaid second fastener, no other structural member is contiguous with saidfirst brake head or said second brake head; and (d) said tension memberis comprised of a first parallel wall and a second parallel wall whichextend from a middle section to a first end section and a second endsection, provided that, when said first parallel wall and said secondparallel wall extend past said section towards said first end sectionand said second end section, they are substantially straight without anybends.
 9. The brake beam assembly as recited in claim 8, wherein saidtension member has an upper surface and a lower surface which aresubstantially parallel to each other.
 10. The brake beam assembly asrecited in claim 8, wherein said tension member has a cross-sectionalarea of from about 0.5 to about 5.0 square inches.
 11. The brake breamassembly as recited in claim 8, wherein said tension member has across-sectional area of from about 1.2 to about 2.0 square inches. 12.The brake beam assembly as recited in claim 8, wherein said tensionmember has a first notched section and a second notched section.
 13. Thebrake beam assembly as recited in claim 12, wherein each of said firstnotched member and said second notched member is substantiallycontiguous with said compression member.